Maria Aaltje ("Marianne") Timmer (born 3 October 1974) is a Dutch former speed skater specializing in the middle distances (1000 and 1500 m).

Timmer won gold in the 1000 and 1500 meter races during the 1998 Winter Olympics in Nagano, beating Chris Witty in the 1000m and Gunda Niemann in the 1500m.

She was disqualified after a false start in the 500m race, but a week later she surprisingly won gold in the 1000m, beating out favorites Cindy Klassen and Anni Friesinger by a very slim margin.

[6] At the 2011 Dutch Single Distance Championships in Thialf, Timmer got the third-fastest time on the first 500m, but ran into Marrit Leenstra on the second 500m, and fell.

[7] Her official goodbye took place during the Tijdens het 2011 World Sprint Speed Skating Championships in Heerenveen, on 22 January 2011.

They were married in Las Vegas in 2001, after which he added her to Spaar Select, his skating team, against the wishes of the other skaters, in what a reviewer of his autobiography called a "dominating and intimidating" way.